Objects of class File::Stat encapsulate
common status information for File objects. The
information is recorded at the moment the File::Stat object is created; changes made to
the file after that point will not be reflected. File::Stat objects are returned by IO#stat,
File::stat, File#lstat, and File::lstat. Many of these methods return
platform-specific values, and not all values are meaningful on all systems.
See also Kernel#test.